In recent years, an automatic processing machine (automatic processor) called a “mini-laboratory” for processing photographic photosensitive materials over the counter is being widely spread for expediting services for ordinary users and rationalizes transportation for collection and delivery. A development processing agent for a mini-laboratory is often supplied in the form of a liquid composition formed by dissolving constitutional processing agents in a solvent, such as water because it has such an advantage that a processing solution can be prepared in a simple preparation operation upon use, such as mixing and dilution with water. However, the form of a liquid composition is disadvantageous from the standpoint of transport cost since it is associated with a container for housing a solvent, such as water, for dissolving the components of the processing agent and the composition, and therefore, it is generally supplied in the form of a liquid concentrated processing composition having been reduced in volume by enrichment (in this field of art, the term “concentration” is used instead of the term “enrichment”).
The liquid concentrated processing agent for bleaching and fixing generally has a two-liquid constitution having higher stability than a one-liquid constitution, i.e., it is generally constituted from two parts, a concentrated composition part containing a bleaching agent (hereinafter, sometimes referred to as a bleaching agent part) and a concentrated composition part containing a fixing agent (hereinafter, sometimes referred to as a fixing agent part).
It is also demanded in the development process in a mini-laboratory in addition to the convenience in transportation described in the foregoing that the process is expedited for improving services for users, and the replenishment is reduced for decreasing the emission amount of waste liquids. In order to realize reduction of the replenishment and expedition of the process in the blix step, it is necessary that the concentration of the bleaching agent is increased, and the pH of the blix solution is lowered to maintain bleaching capability. The fixing agent part cannot have a low pH value since the fixing agent is decomposed or deposited by precipitation with a low pH value of the fixing agent part. However, in the case where the bleaching agent part has a low pH value with a high concentration of the bleaching agent, various kinds of components are deposited by precipitation depending on storage conditions or use conditions at either low temperatures or high temperatures, so as to cause troubles in operation in the laboratories and in processing agents. Moreover, it also causes such a problem that the time-lapse stability is deteriorated at a high temperature to lower the bleaching capability due to decomposition of the bleaching agent to a ferrous compound. Therefore, the high concentration and the low pH value of the bleaching agent part have not yet been simultaneously realized although they have been strongly demanded.